TRB’s National Cooperative Highway Research Program (NCHRP) Report 525: Surface Transportation Security, Volume 11, Disruption Impact Estimating Tool—Transportation (DIETT): A Tool for Prioritizing High-Value Transportation Choke Points (TCPs) includes information on DIETT as well as installation instructions and a user guide. DIETT is an electronic analytical tool that calculates direct transportation and economic impacts (costs) of an event that precludes the use of a TCP, and it prioritizes TCPs on the basis of these criteria. DIETT does not calculate replacement costs. Using DIETT’s prioritized sets of outputs, along with other risk information, decision makers will be able to better focus their capital resource, security, and emergency-preparedness planning.

Although DIETT is specifically designed to assist state DOTs and other state security and emergency-preparedness organizations, prioritized state results can be readily merged to identify candidate TCPs for use in regional or national prioritization schemes. Localities and metropolitan areas can also work with area-specific data to assess their TCP priorities. DIETT is designed to prioritize based on direct transportation and economic impacts; however, it can be expanded by adding other criteria of interest to the user and thus offers compatibility with numerous applications.

Users can “download” the zip file for DIETT (usually by reverse clicking the mouse and selecting “save as” menu option). After downloading, the zip file should be decompressed to their local PC. Users can also consult the “DIETT Installation Instructions and User Guide” (Part 2 of NCHRP Rep. 525, Vol. 11) for installation instructions.

NCHRP Report 525: Surface Transportation Security is a series in which relevant information is assembled into single, concise volumes—each pertaining to a specific security problem and closely related issues. The volumes focus on the concerns that transportation agencies are addressing when developing programs in response to the terrorist attacks of September 11, 2001, and the anthrax attacks that followed. Future volumes of the report will be issued as they are completed.